Five things to watch at the U.S. Open

USA TODAY Sports' Reid Cherner breaks down the five most important things to watch at the U.S. Open.

http://archive.greenbaypressgazette.com/VideoNetwork/3740799707001/Five-things-to-watch-at-the-U-S-Openrtmp://cp17277.edgefcs.net/ondemand/&mp4:Brightcove/Brightcove2/29906170001/2014/08/29906170001_3740781174001_US-Open-Preview-v2qc.mp4http://archive.greenbaypressgazette.com/VideoNetwork/3740799707001/Five-things-to-watch-at-the-U-S-Openhttp://videos.usatoday.net/Brightcove2/29906170001/2014/08/29906170001_3740788234001_thumbnail-for-video-3740692746001.jpgFive things to watch at the U.S. OpenUSA TODAY Sports' Reid Cherner breaks down the five most important things to watch at the U.S. Open.SMGVsportsUSA Today Sportstennisvideo big boardU.S. Open01:26